A medical worker guides people queue up for nucleic acid tests at a sampling site in Chaoyang District of Beijing, China, Dec 26, 2020. Beijing reported two new locally transmitted confirmed COVID-19 cases on Friday, local health authorities said Saturday. [Photo/Xinhua] BEIJING - Beijing has tightened epidemic prevention and control measures after new reports of local infections of COVID-19. Several locally transmitted cases have recently emerged in the districts of Chaoyang, Xicheng and Shunyi in Beijing, sounding the alarm bell again in epidemic prevention and control. On Friday, Beijing reported two new locally transmitted confirmed COVID-19 cases, both in the Shunyi District. Pang Xinghuo, deputy director of the municipal center for disease control and prevention, said on Saturday that Beijing has been conducting mass testing in key areas, and five people, all close contacts of the two cases reported on Friday, have tested positive for COVID-19. The possibility of more cases could not be ruled out as further testing is underway, Pang told a press conference. The Shunyi District has entered a coronavirus "wartime state" with tightened personnel flow management and mass testing in progress, executive deputy district chief Zhi Xianwei told reporters. Zhi said the district activated an emergency response plan, doing epidemiological surveys, source tracing, nucleic acid testing, community management, and environmental disinfection. Authorities in Shunyi planned to conduct nucleic acid testing for 800,000 people, said Zhi. By Saturday noon, around 120,000 people had received tests.